Low monomer foam

Abstract

A process for producing a two component polyurethane foam, which process comprises mixing (A) a polyol resin component; (B) an isocyanate component having a free monomeric diisocyanate content of not more than 2% by weight; and (C) a catalyst blend comprising at least two catalytic materials selected from (a) organometallic catalysts, (b) amines and (c) isocyanurate catalysts.

1 . A process for producing a two component polyurethane foam, which process comprises mixing 
 (A) a polyol resin component;    (B) an isocyanate component having a free monomeric diisocyanate content of not more than 2% by weight; and    (C) a catalyst blend comprising at least two catalytic materials selected from (a) organometallic catalysts,(b) amines and (c) isocyanurate catalysts.    
     
     
         2 . A process according to  claim 1 , wherein the catalyst blend comprises an organometallic catalyst selected from dibutyltin dilaurate, lead napththanate, cobalt napththanate, dibutyltin dilauryl mercaptan, dibutyltin bis(isooctyl maleate), dibutyltin bis (methyl maleate), dibutyltin bis(isooctyl thioglycollate) and dibutyltin diacetate.  
     
     
         3 . A process according to  claim 1  or  claim 2 , wherein the catalyst blend comprises an amine selected from tri(3-dimethylaminepropyl)amine), N,N,N′,N″,N″-pentamethyldiethylenetriamine, bis(dimethylamino) ethyl ether, dimethylcyclohexylamine, N,N,N′,N′-tetramethylethylenediamine, dimethylethanolamine. 2-(2-dimethylaminoethoxy)-ethanol and triethylene diamine.  
     
     
         4 . A process according to one of the preceding claims, wherein the catalyst blend comprises an isocyanurate catalyst selected from potassium acetate, potassium octoate, N, N′,N″-tris-(dimethylarminopropyl) hexahydro-s-triazine, bis-(3-dimethylaminopropyl) isopropanolamine, n-(2-hydroxypropyl)-n-trimethylammonium formate and other quaternary ammonium salts and metal salts. and Baxcat 0.  
     
     
         5 . A process according to any one of the preceding claims wherein the polyol resin component (A) and the catalyst blend (C) are mixed with the isocyanate component (B).  
     
     
         6 . A process according to any one of the preceding claims, wherein the isocyanate of component (B) has a free monomeric diisocyanate component of not more than 0.5% by weight.  
     
     
         7 . A process according to any one of the preceding claims, wherein the mixture or the foam is provided into voids in components on a continuous production line or in discontinuous production.  
     
     
         8 . A two component polyurethane foam obtainable by a process according to any one of the preceding claims.  
     
     
         9 . Use of a foam according to  claim 8 , as a sound and/or vibration absorber.  
     
     
         10 . A process for the production of a two component polyurethane foam substantially as hereinbefore described with reference to the Examples.